1. Field of the Invention
The present invention relates to a film magazine used for loading a photo film, wound around a spool in advance, with a camera.
2. Background Arts
A roll film of brownie size (brownie film) is not contained in a cartridge, so the roll film in the market is wound up on a feeder spool in a roll form using a light-shielding paper. The feeder spool, on which an unexposed film is wound up, is loaded in the film-loading chamber of the camera. Then, an empty spool (take-up spool) for taking up the roll film is loaded in a film take-up chamber of the camera.
An exposure to a picture frame is taken after drawing the unexposed film by a predetermined amount from the feeder spool. The exposed picture frame is wound up on a take-up spool. The whole film is wound up on the take-up spool after completion of the exposure. Then, the take-up spool is taken out of the film take-up chamber and brought into a photo lab. Thereby, the feeder spool in the film-loading chamber becomes empty, since the whole film wound up on the feeder spool is drawn out after completion of the exposure. The empty feeder spool is taken out of the film-loading chamber at the next exposure, and is loaded in the film take-up chamber to be used as the take-up spool.
The brownie film has 120 type and 220 type with same width. The 120 type Brownie film is made of the film, the light-shielding paper longer than the film, and a splice tape. The light-shielding paper is adhered to the film by putting the splice tape on leading and trailing ends of the film such that the leading and the trailing end portions of the light-shielding paper extend off the leading and the trailing ends of the film respectively.
In the 220 type Brownie film, the light-shielding papers are adhered to the leading and the trailing end portions of the film by the splice tape. Since the light-shielding paper covers only the leading and trailing end portions, the 220 type Brownie film becomes thinner than the 120 type Brownie film because of the thickness of the light-shielding paper.
It is difficult to load the Brownie film into the camera due to a long film width. For that reason, a film holder, attachable to the main body of the camera, is well known. (For example, Japanese Patent Laid-Open Publication No. 11-305328.)
The film holder retains the feeder spool and the take-up spool in a rotatable manner, and has a pressure plate between those spools. The front face of the pressure plate is exposed through an opening provided in the film holder. The opening is covered by a mask plate when the film holder is removed from the main body of the camera. A pair of guide rollers is provided on both sides of the pressure plate in the film feeding direction in order to form a film exposure station for exposing the film in front of the pressure plate. The film is drawn from the feeder spool and is threaded onto the take-up spool through a film feeding path connecting a first guide roller (which is closer to the feeder spool), the front face of the pressure plate, and a second guide roller (which is closer to the take-up spool).
The film, which is wound up on the feeder spool with the emulsion surface facing inward on the roll, is advanced to the first guide roller while turning the emulsion surface outward to form an xe2x80x9cSxe2x80x9d shape.
When advancing the roll film from the first guide roller to the take-up spool, the roll film with the emulsion surface facing outward is turned in xe2x80x9cSxe2x80x9d shape so that the roll film is wound up on the take-up spool with the emulsion surface facing inward on the roll again. Thus, the roll film is being fed such that the emulsion surface of the roll film is turned inside out. (For example, Japanese Patent Laid-Open Publication No. 11-119330.) This form of film feeding has an advantage of reducing the width of the film holder. Further, this form of film feeding can be applied not only to the 120 type Brownie film, but also to the film of 220 type Brownie film with no light-shielding paper behind the film.
Notwithstanding high rigidity, the film is curled since it has been wound about the feeder spool for a long period. In addition, 120 type Brownie film with the light-shielding paper behind the film is more rigid than that of the 220 type Brownie film. Therefore, when the film is wound up on the take-up spool, the film, particularly the 120 type Brownie film may get loosened to cause a rise from the second guide roller or a curl in the film width direction perpendicular to the film feeding direction. As a result, the behavior of the film feeding becomes unstable.
Some cameras have a bar code sensor or a data recording device to reads or records data while feeding the film. The bar code sensor or the data recording device is located at a position to face the second guide roller. If the film gets loosened, the distance and the relative speed between the film and the second guide roller become unstable. In that case, data reading or recording process becomes improper.
To solve that problem, it is known to provide a subsidiary guide roller in a position between the take-up spool and the second guide roller. The film is loosened only in the area between the take-up spool and the subsidiary roller, so that the film is parallel to the focused plane of a lens system of the data recording mechanism. (For example, Japanese Patent Laid-Open Publication No. 11-119330.)
It is also known to provide a rib on an inner wall of the camera facing the first guide roller for preventing the looseness of the film. In that case, the film is nipped between a head of the rib and the first guide roller to prevent loosening so as to facilitate proper scanning (Japanese Patent Laid-Open Publication No. 11-119329).
However, in the invention of the Japanese Patent Laid-Open Publication No. 11-119330, additional space inside the film magazine is necessary for disposing the subsidiary guide roller in the proximity of the second guide roller. As a result, the film magazine is upsized. In the invention of Japanese Patent Laid-Open Publication No. 11-119329, there is a problem that the roll film is scratched by the rib which is disposed to contact the surface of the film.
An object of the present invention is to provide a compact film magazine which prevents a roll film from loosening.
Another object of the present invention is to provide a film magazine which prevents scratches on the roll film while preventing the roll film from loosening.
To achieve the above objects, the film magazine of the present invention provides a first guide roller which turns emulsion surface of the roll film outward and feeds the roll film from a feeder spool to a film support plate, a second guide roller which turns the emulsion surface of the roll film inward and feeds the roll film from the film support plate to the take-up spool, and a roller which is on the opposite side of said first or second guide roller with respect to a film feeding path. When the roll film gets loosened to becomes away from the film feeding path while being fed from the feeder spool to the first guide roller or from the second guide roller to the take-up spool, the roller contacts the roll film to prevent loosening. In addition, a rib is provided in a widthwise direction of the roll film along with the roller. When the roll film gets loosened to become away from the film feeding path, rib contacts the end portion of the roll film in the width direction to prevent loosening.
The film magazine includes a film holder for retaining the roll film and the magazine body for covering the film holder. It is preferable that the roller is attached to the magazine body to protrude into the film feeding path.
According to the present invention, it is possible to provide the compact film magazine in which the roller and the rib can regulate loosening of the roll film while feeding. Accordingly, it becomes possible to prevent improper feeding and/or the scratches on the roll film.